奥运开幕式大揭秘：小贝亲自驾驶快艇？

The theatrical tour de force included a series of dazzling spectacles, from a 40ft oak tree rising serenely from a grassy mound, to a towering 18metre Voldemort character roaming around the stage.

Today we can reveal some of the secrets and technical achievements - until now have been shrouded in the strictest secrecy - which it took to produce this breath-taking performance.

The NHS scene used 1,200 volunteers from UK hospitals, including 600 nurses. The giant baby was made from fibreglass paper. Switches lit duvets on the 320 beds.

Thirty-two actresses were dressed as Mary Poppins to descend on wires attached to rigging which could support 25 tons (the weight of five elephants). They carried umbrellas with lights attached.

High-powered fans inflated the seven fabric chimneys, up to 100ft high, from trap doors in the stage. Alongside them, five 32ft long, 9ft-wide steam engines made of steel, aluminium and wood were assembled by ten crew members to help represent the Industrial Revolution.

Amber lights lit in sequence created the illusion of a 100ft molten steel river, with pyrotechnic smoke and ‘dry ice’ as the steam. The steel ‘flowed’ into a 39ft diameter trough to form an aluminium ring, which was raised to join four other rings flying in on cables to form the Olympic symbol 328ft above the stadium. The 30-second shower of sparks was real, with actors and crew protected with fireproof costumes.

Despite rumours that David Beckham wasn’t actually driving the speedboat — named Max Power — that sped him down the Thames, organisers insist he was operating the controls, with other crew members on hand just for safety (though they admit he didn’t dock the boat himself). Apart from close-up shots of Becks, the entire trip was filmed live, overseen by Billy Elliot director Stephen Daldry.

Stuntman Gary Connery dressed as the Queen to leap from a helicopter 550ft above the stadium. Mark Sutton, a former soldier, jumped as 007. They had taken off from Stapleford Airfield in Essex and hovered over London for 30 minutes before the jump — then landed outside the stadium, next to Anish Kapoor’s steel tower.

The 75 ‘dove bikes’, 70 ridden by volunteers found on internet cycling forums, rehearsed in secrecy. The fabric wings had tiny LED lights and were operated by aluminium rods attached to the handlebars which riders pressed to create the flapping effect. Bob Haro, who created the flying bike scene in ET, choreographed the sequence.